1. Field of the Invention
The present invention relates to an apparatus for automatically controlling the correspondence between the numerical codes of telephone subscribers (subscriber numbers) and the different transmission and distribution identification codes of the telephone pair assigned to each subscriber.
2. Description of the Prior Art
It is known that a subscriber line consists of two wires forming a telephone pair. This pair is continuous from the main distributing frame in the telephone exchange or central office to the subscriber's telephone set. Said pair establishes a route via the following two cables:
a transmission cable which extends between the main distributing frame and the subdistribution frame (subdistributor); PA0 a distribution cable which extends between the subdistribution frame and the subscriber's telephone set. PA0 means for successively entering into the apparatus the numerical codes and constitution numbers of subscribers of the technical file to be checked; PA0 connectors to be attached to the terminals of a subdistribution frame; PA0 a test unit comprising a microprocessor which is programmed for storing the data entered into the apparatus and for initiating transmission of a coded signal to the transmission and distribution cables of the pairs to be tested, means for detecting said signal in order to check whether the designated constitution is correct or not in the corresponding pairs of the transmission and distribution cable terminals of the subdistribution frame; PA0 means for displaying the results of said test. PA0 a program for entering the numerical codes and constitution numbers of subscribers; PA0 a program for specification of correspondence of subdistribution-frame terminals; PA0 a program of continuity tests; PA0 a program for assignment of a terminal for transmission or distribution; PA0 a program for returning to the start-of-cycle position.
All the cable pairs have an identification code, namely a transmission code and a distribution code. Each of these two identification codes is designated as a "constitution". In consequence, there are two constitutions for each individual telephone number.
For example, in the case of a subscriber number such as 739 33 20, there is a corresponding transmission identification code such as 152.10.6 and a distribution identification code such as 2.12.4.
All these identification codes are listed in a file known in France as the "technical subscriber-file".
It is apparent that this file must provide an absolutely faithful record of the state of the main distributing frame and of the subdistributors which are dependent on the main frame.
In consequence, updating of said file is necessary after each modification carried out on the telephone system. Especially when connecting new subscribers, it is found that, if identification of new cable pairs has not been followed-up, the result is a slow but inexorable disorganization of the technical subscriber-file.
According to French postal administration sources, the percentages of error of these files can attain 35%, thus entailing the need for total file reorganization at periodic intervals.
This operation consists in following by hand the jumper wires (cross-connections) which establish connections on the one hand within the subdistribution frames between the different transmission cable terminals and the different distribution cable terminals and, on the other hand, within the main distributing frame, between the different transmission cable terminals and the different subscriber numbers.
This operation is at present performed entirely by hand, is both tedious and time-consuming, and is in fact regarded as a punishment by operators. Furthermore, this manual operation is not wholly devoid of errors.